Method for making rolled hollow metal articles



Nov. 10, 1936. c. G. STEELE ET AL METHOD FOR MAKING ROLLED HOLLOW METALARTICLES Filed Dec. 9, 1951 5 Sheets-Sheet l .Zwswmaas Nov. 10, 1936. c.G. STEELE ET AL METHOD FOR MAKING ROLLED HOLLOW METAL ARTICLES FiledDec. 9, 1951 5 Sheets-Sheet 2 wx lHH iin rzzzwz'azas 1 31 Sraazs 77H5'15 wsws' mm? q,

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METHOD FOR MAKING ROLLED HOLLOW METAL ARTICLES Filed Dec, 9, 1931 5Sheets-Sheet 3 Nov. 10, 1936.

'c. G. STEEILE ET AL METHOD FOR MAKING ROLLED HOLLOW METAL ARTICLES 5Sheet s-Sheet 4 Filed Dec. 9, 1951 Wis-4x72 47125 55: 525525WHISJZBVEJVS BY W M JIIUJPNEYS.

Nov. 10, 1936. TEELE ET A 2,060,779

METHOD FOR MAKING ROLLED HOLLOW METAL ARTICLES 5 Sheets-Sheet 5 FiledDec. 9, 1931 55 Mayra-1.22s

5. WWW w J y E UNITED STATES PATENT OFFICE METHOD FOR MAKING ROLLEDHOLLOW METAL ARTICLES Charles G. Steele and Walter H. Stevens, LosAngeles, Calif.

Application December 9, 1931, Serial No. 579,888

5 Claims.

Our invention relates to an apparatus and method for transverse rollingof metal articles, preferably hollow metal articles, between a pluralityof rolls, which rolls, during the rolling op- 5 eration have their axesat fixed distances apart. In this type of rolling there are usually tworolls which may be considered as supporting or form rolls, thesegenerally having a configuration to fit the finished article. With thesetwo supporting rolls there cooperates a forming or pressure roll. Thispressure roll has a segment cut out, a convenient manner being to havethis with a flat side, such flat side forming a chord of the roll, andthe articles to be rolled are inserted between the two supporting rollsand the forming roll while this flat or non-operative surface is locatedabove the supporting rolls. The articles may then be insertedtransversely to the set of rolls or inserted longitudinally of the axisof the rolls. In this type of rolling a single rotation of the pressureroll gives a complete, finished article.

Our invention relates principally to rolling hollow blanks without amandrel by which not only the outside but the inside diameter may be re-25 duced and thus retaining a wall thickness in even the most reducedparts substantially equal to that of the original blank at theseparticular parts.

Another feature of our invention relates to using a pair of supportingrollers having a complementary configuration to that of the finishedblank and rolling the articles transversely by means of a forming orpressure roll which has a general spiralled cam-shaped increase inradius to force a reduction of the blank and then terminates the rollingwith surfaces of constant radii.

A further feature of our invention is that the blank is rotated acomparatively large number of times or turns on the supporting rollerswhich are of relatively small diameter compared with the pressure rollfor one rotation of the pressure roll and during the action of the lastsection of the pressure roll the radii at various places are constant.

In this type of rolling apparatus and in the method of operation, one ofthe objects of our present invention is to .provide adjustment for thevarious rolls to simultaneously regulate the distance apart whereby whenthe pressure roll is lowered. to roll comparatively small articles, thetwo supporting or form rolls are brought together, but the arrangementis always such that the axis of the form roll is vertically above themid distance between the axes of the two supporting or form rolls. Thiscontrol or adjustment of the relative position of the rolls alsoseparates the supporting or form rolls when the pressure roll iselevated to accommodate articles of larger diameter. The ratio ofvertical movement of the pressure roll to the lateral or horizontalmovement of the supporting or form rolls is so related that the articlesundergoing the rolling are adequately supported while being reduced bythe pressure roll. This is accomplished by the simultaneous verticalmovement of the pressure roll and the lateral to and from movement ofthe two form or supporting rolls.

Another object and feature of our present invention is employing in thepressure roll a cam or series of cam surfaces for reducing the articleto be treated as distinguished from the eccentric type of reducingsurfaces or sections of the pressure roll. The cam construction allows agradual reduction of the article under treatment with a gradual pressurebeing brought to bear on the article by the pressure roll. By the camconstruction of the reducing sections of the pressure roll, pressureswhich would distort the finished article or jam the machine may beavoided.

Another object and feature of our present invention relates to therolling of hollow articles in such a manner that these may havediiferent sections considered longitudinally reduced in differentdegrees or in different shapes but maintaining the wall thicknesssubstantially constant. In other words, by our invention, tubular blanksof substantially a constant wall thickness or of different wallthicknesses at various parts may be rolled transversely, changing theconfiguration to conform with that of the finished article in one turnof the pressure roll and in which the wall thickness of the finishedarticle is substantially the same as that of a similar section of theblank. By our method of rolling, a reduction in diameter of the articlecauses an extension of its length.

Another object and feature of our invention relates to a clutch which isautomatically operated to stop the pressure roll at each rotation withthe fiat side down for withdrawing the rolled article and inserting anew blank. Together with this clutch we incorporate a manual controlwhich will allow the clutch to be retained in driving position tocontinuously drive the pressure and the supporting rolls.

Our invention is illustrated in connection with ,the accompanyingdrawings, in which:

Fig. 1 is a side elevation of our invention taken in the direction ofthe arrow I of Fig. 2;

Fig. 2 is a plan taken in the direction of the arrow 2 of Fig. 1;

. Fig. 3 is an end elevation taken in the direction of the arrow 3 ofFig. 1;

Fig. 4 is a partial elevation in partial section of one of the housingsfor the rolls;

Fig. 5 is a horizontal section on the line 5-5 of Fig. 4 in thedirection of the arrows;

Fig. 6 is a vertical section on the line 5-5 of Fig. 1 in the directionof the arrows;

Fig. '1 is a section on the line 'I--'I of Fig. 1 in the direction ofthe arrows;

Fig. 8 is an elevation of a blank;

Fig. 9 is an elevation of a finished article;

Fig. 10 is a diagram to illustrate a reducing roll having a cam reducingsurface. the cam surface being exaggerated relative to the diameter ofthe roll;

Fig. 11 is a diagram illustrating prior attempts to use an eccentricreducing surface on the reducing roll, the eccentric being exaggeratedrelative to the diameter of theroll.

In the drawings, referring first to Figs. 1 and 2, I employ the reducingroll stand II, a gear drive II, a main clutch 13, a reducingtransmission gear i4, and an electric motor l5 as a source of power. Thedrive gears connect the rolls by spindles It.

The reducing roll stand, the transmission gears I 2, and the reducinggears l4, are illustrated as mounted on longitudinally extending tracksH,

which are firmly secured to the floor IS. The reducing roll stand isconstructed with two end pedestals I! which have lugs 20 at the oppositesides for bolting the tracks I! and each of these has internal verticalguides 2|, an enlarged lower opening 22, and a horizontal guide base 23for the lower rolls. A head piece 24 is mounted on the sides 25 of theends of the stand. The pressure roll-23 has end axles 21 which aremounted in sliding bearings 23. This is formed in the manner of a splitbearing having a lower half section 23 and an upper half section 30.There are guide plates 3| which hold these bearing sections in positionin the guide 2|. The lower supporting or form rolls 32 each have axleends 33, these being mounted in a horizontally slidable bearing block34, which blocks are open at the top and are arranged to slidetransversely on the base 23 and are guided by side plates 35.

The gear drive l2 has a pair of pedestals 36 also connected to thetracks II. In the pedestals there is a central drive gear 31 which hasan axle 33 extending through the housing and being journaled therein inany suitable manner and .having one element 39 of the clutch. The gear31 meshes with two lower gears 40 and M, these each having their ownshaft suitably journaled in the pedestal 35. A large or upper gear 42has its own, 'shaft also Journaled in the pedestals. Thus the drive iscommunicated from the driving shaft 33 through its gear 31 to the gears40 and 4| at the bottom and also to the gear 42' at the top. The shaftcarrying the gears 40 and 4| and also the shaft carrying the gear 42 areconnected by spindles to the shafts of the form roll 32 and to the shaftof the pressure or formingrnli 25, thereby communicating the drive tothe rolls. The reduction gear mechanism need not be described in detailas it is not part of our immediate invention, except to state that thishas a power transmission shaft 43 on which is slidably mounted thesecond element 44 of the clutch I3. As the drive from the electricmotoris constant and the clutch element (is constantly driven,therefore, when the clutch is engaged it rotates the rolling gears andon disconnection these gears become stationary.

The general shape of the ripper or pressurein the direction of the arrow49. The roll is designed to first obtain a pressure engagement on acylindrical object to be worked at substantially the center of the rolland a pressure exerting portion is formed as a cam 50. This cam has astarting end 5| from the cylindrical portion 48 of the roll. The camgradually merges so there will be no abrupt pressure brought to bear onthe article to be rolled. The final stages of this cam section indicatedat 52 are made on the radius 53, this having the center 45 so that thearticle at the center has a finished cylindrical rolling after beingpressed inwardly or reduced to the desired extent. The particularconfiguration of the roll is dependent on the articles to bemanufactured.

In Fig. 8 a hollow cylindrical blank is indicated at 53. This isindicated as having a wall thickness 54. Fig. 9 illustrates a finishedarticle 55, in this particular instance being an axle blank and having atapered section 56 with a long taper, an opposite taper 51 at the end,these tapers diverging from the line 58. The opposite end 59 has acylindrical section illustrated as of the same diameter as the blankwith the inclined shoulder 60 adjacent thereto. Therefore, to form anarticle of this type the pressure roll will have a cam-shaped pressingcenter which will engage the blank 53 at about its center and reducethis to form the taper 56. This reduction gradually elongates the metalof the blank so that the finished article is longer than the blank. Thereducing pressure forms the tapered shoulder 60. In the present instancethe portion 59 is left substantially the same diameter as the blankinitially used. The end taper 51 is also formed by a cam-shaped surface6i on the pressure roll which commences its action subsequent to thepressure at thecenter so that the elongation is substantially fullyaccomplished before the end section 6! is started. The operation is suchthat it leaves a constant thickness wall 62 when rolling hollowarticles. This wall is substantially of constant thickness provided itsthickness was the same in the original blank because the reduction ofthe tubular blank does not increase or decrease materially the thicknessof the wall but causes an elongation lengthwise which accommodates thedisplaced metal forced from the center, usually in both directions.

The supporting or form rolls 32 are formed with a surface configurationdesignated generally at 63. This configuration is such as to accommodateand support the finished article; and in the illustration given requiresan enlargement 54 to accommodate the shoulder portion 60 of the articleand an enlargement 65 at the end to accommodate the contracted end 51 ofthe article. It is obvious that the pressure and supporting rolls willbe changed in their configuration in accordance with the article to berolled and that the pedestals of the roll stand may be placed furtherdistance apart for the mounting of longer or shorter rolls. The articlesto be rolled may'be entered between the rolls from one side while as isused in the art. The headpieces on each side of the machine areconnected by a top bar 68 which is illustrated as being in the form of achannel having a web 81 and two flanges 88 (note Fig. 6). This rigidlysecures the two pedestals of the roll stand spaced proper distancesapart. If the distance is to be changed the top bar must necessarily beelongated or shortened. In the center of each head bar 24 there. is acentral bore 89 in which is fitted a bushing 10, this having a flange IIat the bottom and is bolted in place by bolts I2. This bushing isthreaded, and extending therethrough are the thrust screws 13. Thesethrust screws have a conical enlargement 14 adjacent the top forming athrust bearing for the complementary conical bearing I5 in the ends I8of the transverse beam 11, this beam extending across between the twopedestals and being supported on each of the thrust screws. The lowerend I9 of the thrust screw bears in a thrust socket 19 in the upper half30 of the bearing 28. Four adjustable tension rods 80 extend from theend I6 of the beam 11 and engage below the bottom half 29 of the bearing28. These are tightened sufficiently to give a proper fit to the bearingon the end shaft 21 of the pressure roll. It will thus be seen that theweight of the pressure roll when there is no work being operated upon iscarried by the thrust screws" to the beam 11 and from the end 16 of thisbeam the rods 80 support the bearing 28 and thus suspend the pressureroll.

The manner of operating the pressure roll to raise and lower'thiscomprises an electric motor 83 mounted in the center of the beam 11 anddriving shafts 94 extending in opposite directions from the motor. Theseshafts extend through bearings 88 also mounted on the beam I1 driving abeveled gear 88 (note Figs. 5 and. 6)

The beveled gear 88 meshes and drives a complementary beveled gear 81 ona transverse shaft 88 which extends along cross arms 89 mounted I on theends of the beam 11 and extending over the pedestals having the journalsfor the rolls. This shaft has bearings 90 in this cross arm. It isprovided with a worm 9| which meshes with a worm wheel 92 on the spindieend-93 of the thrust screw I3, thus rotating this screw. One directionof rotation threads the screws 13 on both sides of the roll standdownwardly and thus lowers the pressure roll to the proper position onthe work, the upward thrust in rolling being taken by the threads on thethrust screws and in the bushings 10.. Conversely, when the thrustscrews are rotated in the opposite direction to raise the pressure rollthe rods 80 lifting on the lower section of bearing of this roll elevatethe roll. v

The drive to separate or to thrust together the supporting or form rollsis as follows, having reference particularly to Figs. 1 through 6. At-

each side of each pedestal there is a vertical divided shaft 94 withsplined connecting sleeve 94' journaled at the top 95 in the cross arm89 and at the bottom in a journal 98 extending outwardly from the lowerpart of the pedestal. At the upper end each of these shafts carries aworm wheel 91 which meshes with a worm 98 on the outer ends of the crossshaft 88. At the bottom of each vertical shaft 94 there is a beveledgear 99 which meshes with a beveled gear I00 each splined to atransverse screw IIlI. This screw is journaled in a journal bracket I02on lugs 20 at the lower portions of the pedestal I9. Such screws operatethrough a threaded bushing I03 in each leg of the pedestal. They haveenlarged heads I04 which fit in the sockets I05 in the bearing blocks 34which form the bearings for the axle shafts of the lower, that is, theform or supporting rolls. Therefore, in one direction of rotation ofthese vertical shafts 94, the screws IOI are threaded inwardly and thusthrust the bearing blocks 34 toward each other, bringing the supportingor form rolls closer together and in I this same action the center andupper pressure or reducing roll is lowered. Conversely, in a reversedirection of the shafts 94 the screws IOI are withdrawn outwardly, thusseparating the hearing blocks 34 and the lower rolls mounted therein andsimultaneously the thrust screws 13 are threaded upwardly, causing theelevation of the upper roll. It' will thus be seen that the three rollswhich coact together in rolling and reducing articles are simultaneouslyseparated and brought together and the proper gear system may be chosenand pitch of all of the screws so that the vertical distance between thelower rolls and the upper pressure and reducing roll bears a correctrelation to the horizontal distance between the two lower supporting orform rolls.

The movable clutch element 44 is as follows, having referenceparticularly to Figs. 1 and 2:

A pair of journal blocks I08 are each secured to the rail I1 and may beadjusted therein longitudinally of such rail. Journaled in these is arock shaft I0'I extending transversely from one block to -the other,which rock shaft has a rocking lever I08 connected thereto. This leverhas a sliding link I09 connected thereto, the upper part II 0 of whichis pivoted to the lower part. The free end III has a pin thereon whichis adapted to engage a projecting pin II2 of a cam type on the shaft onthe upper gear 42. The arrangement-is designed whereby when the flatside of the roll 26 is opposite the lower rolls the cam pin engages thepin on the end III of the link and raises this. A yoke H3 is connectedto the rock shaft I01 and connects with a collar II4 fitted on theclutch eement 44. Therefore, when the link I09 is pulled up through theaction of the pressure roll the clutch element 44 is disengaged from theclutch element 39, thus allowing the gears and hence the drive to cometo a stop. It is necessary to reset the clutch manually, which is doneby the following mechanism:

An elongated rock shaft H5 is mounted in journals IIS on the floor, andthis has a series of vfoot pedals III extending outwardly from themachine. A lever II8 connects to the rock shaft and the link II9 leadsto the rocking lever I08. Springs I20 underneath the foot pedals andengaging the fioor tendto elevate these pedals, causing a thrustingupwardly on the link II9, thus rocking the lever I08 down anddisengaging the clutches. This action pulls down on the link I09, theupper portion IIO of which has a cam I20A, which engages with a camI-20B, on the pedestal 38, and thrusts the pin III outwardly. This upperend is normally retracted by a spring I20C. This action causes the pin 0to clear the cam pin H2 and allow the manual resetting of the clutch.Then if the pedal is not held down the drive will be continuous and thisis of use where articles can be removed and inserted between the rollsat each rotation. There is suflicient slip connection between thevarious links and levers to allow the manual setting and continuousoperation as well as the intermittent operation.

One of the features of our invention, as above mentioned, is that thereducing portion of the pressure roll is formed in the manner of a camand, of course, if there are a number of difierent portions of thearticle to be reduced in diameter, there will be a plurality of thesecams. We use the cams in contradistinction from the prior art in whichattempts have been made to use eccentric reducing surfaces. The cams areusually formed somewhat in the manner of a spiral with the smallestradius being at the initial point of grip on the work and the point ofmaximum radius being that at which the reducing operation is completedon the work. Following this the pressure roll usually has a cylindricalsection whose radius equals from the axial center of the roll to thepoint of maximum radius of the cam.

In Fig. 10 we illustrate in diagram a form of the pressure roll 26. Inthis case the center 45 is the axial center of the roll on which itrotates.

.41 is the radius from the center to the initial starting point of thegrip of the roll. The roll rotates in the direction of the arrow 49. Inthis case the cam 50 is illustrated as having its initial workingsurface start at substantially adjacent the part 48 which issubstantially cylindrical. The cam gradually increases in radius fromthe center 45 and, in fact, may be made somewhat in the form of a spiralhaving the radius gradually increase from the radius of the circle ofthe roll to the maximum required for the reduction of the work in hand.The final portion I 2| of the cam is indicated as having the radius 53and the remaining portion I22 of the rolling surface as having a radiusI23, this portion being a cylindrical section. It will thus be seen thatby this construction of cam the cam surface is greater than 180 andgives a gradual increase in radius without dipping inside of the circleformed by the radiusof the roll at its place of smallest diameter. Thiscircle is indicated dotted at I24.

Referring to Fig. 11, the axial center of the roll is designatd at I25.This has a flat side I26 and in this instance the radius to the pointI21 of the initialgrip on the work is indicated as of the same radius"as that of the roll having the cam. In this case an eccentric rollingsurface is illustrated having a center I28 which, as will be seen, isoffset from the center I25 and an eccentric curve I29 would illustratethe shape of such a reducing surface. It will be noted that this surfacefor a portion I30 is inside of the portion I3I of the circle having theradius 41 at the center I25. The remaining portion of this circle isindicated dotted at I32. It will, therefore, be seen that the eccentriccrosses the line of the circle substantially at the point I33. If thistype of roll is used the initial point of the grip on the work isrepresented by the part I2! of the roll which is of greater radius thanthe portion I30 from the center I25. Therefore, there would be a releasein pressure on' the work while the roll turned without having effectiveaction on the articles being operated upon. The pressure would thensuddenly be brought to bear on the work substantially at the point I33of the roll and thus would increase to the maximum at the point I34,which is on the radius I35 of the eccentric. The portion I36 isindicated as having a radius I3'I with I25 as the center. It will,therefore, be seen that when the cam reducing surface is used there is agradual and increased pressure being brought on the work being handled,giving a continuous reduction in diameter of this part. This tends toelongate the article. With the eccentric construction a portion of thesurface of the roll does ineffectual work and then a more or less suddenpressure with a, rapid reduction is brought on the work. This causes anineffectual rolling of articles rolled transversely by.our procedure. Weare under the impression that the camshaped reducing roll is one of thefactors which enables us to roll tubular blanks having cylindricalexterior and interior surfaces with a constant thickness in such amanner that this blank may be reduced in diameter at various portions tothe desired extent and that the finished article will have substantiallythe same wall thickness as the original blank at both the reduced andnonreduced sections. The metal which is displaced in reducing thediameter is forced lengthwise of the article and thus elongates sucharticle.

On account of the supporting rollers being of quite small diametercompared to the forming or pressure roll the blank is given quite anumber of turns or rotations for one rotation of the pressure roll tooperate on the blank as various sections of constant radii designatedI23 (Fig. give the blank what might be termed a cylindrical rollingduring the final stages of the operation. The portion of the pressureroll having the constant radii I23 is suflicient to give at least onecomplete rotation to the blank. The wall thickness of the finished blankat any particular section is maintained substantially equal to that ofthe original blank at this section because the blanks are reduced byrolling without a mandrel. The supporting rollers have a configurationcomplementary to that of the finished blank and at every diametricalsection the radius is constant. Therefore, as the forming or pressureroll which has a spiralle'd cam-shaped increase in radius as it rotatespresses the blank to change the exterior configuration to becomplementary to that of the supporting rollers but as there is nomandrel on the inside of the blank the metal of the blank meeting noresistance at the parts which are reduced is pressed inwardly. If thereduction in diameter of the blank is very great the pressing inwardlyof the inside portion of the blank does not quite take care of thereduction so that in such there is some elongation of the blank but thisis taken care of by the design of both the supporting rollers and thepressure roll.

An important feature of our invention in rolling hollow blanks without amandrel is that the inner skin of the blank is not injured or distortednor is it cut away or pressed in any manner. Therefore, this inner skindoes not materially lose in strength in the rolling operations as thefibres of the skin are more or less undisturbed.

Various changes may be made in the details of construction withoutdeparting from the spirit or scope of the invention as defined in theappended claims.

We claim:

1. The method of rolling hollow blanks without a mandrel, rotating ablank on its axis without bodily displacement of the blank and at thesame time applying pressure in a radial direction on the blank, thepressure gradually increasing taining the wall thickness of the finishedarticle substantially the same as the original wall thickness of theblank at corresponding diametrical sections.

2. The method of rolling hollow blanks without a mandrel having acircular periphery and of substantially a constant wall thickness at anydiametrical plane, comprising rotating the blank on its axis withoutbodily displacement of the blank and gradually exerting pressureradially inwardly of said blank, said pressure increasing until theblank is reduced to a predetermined radius, said rolling elongating theblank to form the finished article but leaving the wall thickness of thefinished article at any diametrical plane substantially the same as thatof the blank at the same plane.

3. The method of transverse rolling hollow blanks without a mandrelhaving a circular periphery at different diametrical sections,comprising supporting the blanks on form rolls having a peripheral shapeto conform to the finished article and having circular working surfaces,and exerting a pressure in a radial direction on the blank by a pressureroll having a camshaped pressure surface formed somewhat as a spiral,the pressure roll completing the rolling in one complete rotation, saidblanks having their diameter reduced at the sections acted upon by thecam of the pressure roll, the wall thickness of the finished article andthe blank being substantially the same for corresponding parts, thefinished article being elongated in amount varying with the reduction indiameter, and in the rolling retaining the blank without bodilylongitudinal displacement.

4. The method of rolling hollow blanks without a mandrel, comprisingsupporting a blank on a pair ofspaced supporting rollers having aconfiguration complementary to that of the finished article, exerting aradial pressure on the blank to force the exterior of the blank into theconfiguration of the supporting rollers, the pressure graduallyincreasing while the blank rotates a plurality of times, and thenfinishing the blank by a circular rolling without increase of pressurewhereby the interior of the blank is reduced in diameter at variousportions simultaneously with the exterior of the blank to maintain substantially the original wall thickness at various diametrical sections,said radial pressure increasing in proportion with constantly increasingradii of the pressure roll from its axis. a

5. The method of rolling hollow blanks without a mandrel, comprisingrotating a blank on its axis without bodily displacement. of the blankand at the same time applying pressure in a radial direction on theblank, the pressure gradually increasing to continually change theradius of parts of the blank under deforming pressure while the blankrotates a number of times, said pressure changing the diameter ofdifferent portions of the blank considered longitudinally thereof, thenfinishing the blank by a rolling at least one complete rotation of theblank without reducing pressure, whereby the interior diameter of theblank at various sections is reduced while the exterior is reduced, andthe original wall section at the corresponding sections remainingsubstantially constant, said radial pressure increasing in proportionwith constantly increasing radii of the pressure roll from its axis.

CHARLES G. STEELE.

WALTER H. STEVENS.

